750EF Go Kart

[750ef_Kart]

Hello Everyone,

This is my first post and may be a bit odd. I recently acquired a running '85 GS750EF engine, transmission and wiring harness. I am going to be putting this setup into my go kart / sand rail that I've had for many years and have been upgrading engines along the way.

I am now sitting with a complete engine and tranny (minus exhaust) and this wiring harness and I am looking for some advice on how to wire the engine to get it back into running condition.

I have a wiring schematic printed from carlslater.com but it doesn't appear to be exactly accurate and the EF model seems to be somewhat rare. If anyone could point me in the direction of a good schematic and maybe offer some tips on the essential systems / wiring that I will need to keep it would be very much appreciated.

Right now all I can see myself requiring is ignition, starter, alternator, and possibly the tachometer although this really isn't necessary. I will also need to bypass the starting key as the ignition cylinder wasn't included with the engine.

Again, any help you can lend is much appreciated, I have a lot of experience working on cars but this is my first bike engine!

Thanks very much!

P.S. my apologies if some people perceive it as an insult to the GS series to rip the engine out but the bike no longer had an ownership and was in rough shape!


windows screenshot

[zig06]

Hmmm, just be sure to record the first time you get it driving, the crash should be spectacular! Even so, I did see a quad with a GS550 motor installed and it actually worked pretty good. Just be sure to complete your over head roll cage and consider installing some kind of rear suspension.

[Charlie G]

Welcome. The starter and alternator (stator) should be on the motor. I would think you'd need a wiring diagram. Go to the "Owners" section and introduce yourself there. Basscliff has a website which has manuals you can dpwnload. The wiring diagram is contained in a manual. That motor has about 80Hp and it's going to scoot.

cg

[salty_monk]

It's permanent magnet not alternator. You are going to need a rectifier/Regulator unit.

You'll also need the ignitor box for the ignition (not cheap if you don't have it) as the advance is electronic on those engines. It appears (although I can't really see) that it might be in the pile in the right hand corner near the fuse box & ignition relay. That might be the flasher box though....

The Tach was electronic on that model & took it's pulse from the coil trigger.

The ignition is a wasted spark system so you will need two x 3 ohm coils with 2 plugs going to each one.

You may want to look at putting a baffle in the sump/oil pan as when I was into Lotus 7 replica's ( https://www.google.com/search?q=Lotu...w=1920&bih=993 ) we saw a lot of issues with bike engined cars starving for oil due to the different forces required. Admittedly some of that was caused by running the engine sideways to mate the output to a propshaft so you may be ok...

Don't expect clutches to last too long.... and if it's a foot clutch I would suggest installing the heaviest duty replacement springs you can find. That clutch only has 4 springs so will be impossibly light with stock springs.

I would also expect you to need some kind of jetting kit depending on your pipe setup (assuming you will have minimal muffling on it) & more importantly your air filter setup. As it's a sand rail 4 foam Uni Filters might be best & perhaps even sit them in a box with a snorkel to try to keep the worst of it out.... Dynojet is the kit most use. You may get away with just bigger main jets & moving up the needle (in a 4 wheeler throttle position are not so sensitive so flat spots that might be an issue on a bike are sometimes barely noticeable).

Good luck with your project.

[750ef_Kart]

Thanks for the information everyone, I found a diagram that makes much more sense and just went and verified that all the components are there!

Now I should be able to get it wired up, except that I'm still missing the key + lock cylinder, is there a way to wire the ignition switch to bypass the key?

As for the clutch I'm planning on mounting the clutch handle (which I kept) on a shift lever between the seats and running a rally car style sequential shift.

The exhaust is going to be difficult as I've read these bikes don't run well without a full exhaust, which will not fit, any suggestions?

[tkent02]

Now I should be able to get it wired up, except that I'm still missing the key + lock cylinder, is there a way to wire the ignition switch to bypass the key?

Toggle switch works well.

The exhaust is going to be difficult as I've read these bikes don't run well without a full exhaust, which will not fit, any suggestions?

It will run with whatever exhaust you tune it for.

[750ef_Kart]

Where would this toggle switch be wired in? There's 4 wires coming off the ignition switch harness.

[tkent02]

The two that make the engine run.

The other two wires were for lights.